The technique of using an insulating film made of silicon oxide (SiO), silicon nitride (SiN), or the like for insulating conductive portions in a semiconductor device from each other is known. Furthermore, the technique of using a comparatively low dielectric constant insulating film (which is referred to as, for example, a low-k film) for reducing parasitic capacitance generated between conductive portions is also known.
The method of forming an insulating film over a foundation substrate or layer, forming a determined opening portion in the insulating film by photolithography and etching, and forming a conductive portion, such as a wiring, in the formed opening portion is widely used in the field of semiconductor device production. In addition, the technique of using a photosensitive composition after exposure and development as an insulating film (pattern film) is also known.
Japanese Laid-open Patent Publication No. 2010-056156
Japanese Laid-open Patent Publication No. 2006-278506
Japanese Laid-open Patent Publication No. 2012-053243
A comparatively low dielectric constant insulating film has low film density and low moisture resistance, compared with a higher dielectric constant insulating film. As a result, such an insulating film tends to absorb moisture. Even if a low dielectric constant insulating film is used in order to reduce parasitic capacitance, such moisture absorption may cause deterioration in the performance or reliability of a semiconductor device.